A contrast study on effect of powdered,aminated straw with or without inorganic soil conditioner(calcium sulfate)on soil structure and water-holding capacity in low suction section was made through soil column incubation test.The results showed that the pretreated straw significantly improved soil structure stability,decreased soil structure fractal dimension.Therein the soil with comminuted and aminated straw had a slow acting to improve soil stability.Different pretreatment of straw mixed with soil could make soil porosity connectivity poor in the early stages,and then better with the straw decomposition later.Therein the soil with long straw always kept worse soil porosity than soils with the powdered straw.Furthermore there was a significantly linear correlation between soil aggregate fractal dimension and soil porosity fractal dimension in low suction section.That quantitively explained the effect of the pretreated straw on soil structure and water-holding capacity in low suction section of soil.

Wang Zhen1,Feng Hao 1,2,Wu Pute 1,2,Du Jian 3 (1.College of Water Resource and Architectural Engineering,Northwest Agriculture and Forestry University,Yangling 712100,China; 2.Water and Soil Conservation Research Institute,China Academy of Sciences and Ministry of Water Resources,Yangling 712100,China; 3.College of Agriculture,Northwest Agriculture and Forestry University,Yangling 712100,China);Effects of soil amendment fertilizers on yield and water use efficiency of spring maize[J];Transactions of the Chinese Society of Agricultural Engineering;2009-11